Last updated: 3 October 2026
Reviewed by Jordan Morley, FA Level 2 Football Coach
ERA = (earned runs ÷ innings pitched) × 9. It represents how many earned runs a pitcher would allow per nine-inning game. MLB average ERA varies by era — typically 3.80-4.50 in modern baseball. Below 3.00 is excellent; 3.00-3.80 is above average; above 4.50 is below average. ERA+ adjusts ERA for ballpark and league context (100 = exactly league average; 150 = 50% better). ERA can be inflated by bad fielding, which is why FIP (Fielding Independent Pitching) isolates pitching from defence.
- Earned runs / IP × 9
- MLB modern avg ~3.80-4.50
- ERA+ normalises for park and era
- FIP removes fielder influence
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ERA (earned run average) estimates how many runs a pitcher would allow per nine innings, excluding runs caused by fielding errors — an ERA under 3.00 is considered excellent in modern baseball, while an ERA above 5.00 generally signals a struggling pitcher, though park factors and defensive support behind the pitcher can distort the number significantly.
FAQ
What's considered a good ERA in baseball?
Below 3.50 is strong, below 3.00 is excellent, and sub-2.50 is elite in most eras; league averages fluctuate but typically sit in the 4.00-4.50 range.
Why doesn't ERA count unearned runs?
Runs resulting from fielding errors are excluded because they're considered the fault of the defence behind the pitcher, not the pitcher's own performance.